A great variety of cleaning compositions have been described in the art, that are particularly suitable for pretreating fabrics.
For instance, EP-A-598170 discloses a particular type of cleaning compositions which are aqueous emulsions of a nonionic surfactant system further comprising hydrogen peroxide or water-soluble source thereof and a liquid bleach activator, or any other hydrophobic ingredient which needs to be separated from said hydrogen peroxide.
European patent application number 95203330.6 discloses a particular type of cleaning compositions which are aqueous microemulsions of a bleach activator in a matrix comprising water, hydrogen peroxide and a hydrophilic surfactant system.
However, a drawback associated with such emulsions or microemulsions comprising a peroxygen bleach and a bleach activator, especially when used in laundry pretreatment applications on different kinds of fabrics, e.g., cotton and/or synthetic fabrics (e.g., polyester/polyamides), is that they do not deliver effective performance which satisfactorily meet consumer's needs on all types of stains including greasy stains, enzymatic stains, mud/clay stains as well as bleachable stains. Indeed, there is still some room to further improve the stain removal performance as well as the bleaching performance of such bleach-containing compositions when pretreating a fabric therewith.
It is thus an object of the present invention to provide improved stain removal performance on a wide range of stains as well as improved bleaching performance, especially under laundry pretreatment conditions, i.e., when applied neat onto at least a portion of a fabric before washing said fabric.
Furthermore, another problem associated with such emulsions and/or microemulsions especially with those containing relatively high concentration of surfactants, e.g., about 8% or above, is that important viscosity tends to build up, which makes said emulsions/microemulsions difficult to dispense, and thus unacceptable from a consumer viewpoint.
It is thus a further object of the present invention to provide liquid emulsions or microemulsions comprising a peroxygen bleach and a surfactant wherein the viscosity can be conveniently controlled while maintaining adequate physical stability.
It has now been found that improved stain removal performance is obtained, by using a liquid composition comprising a peroxygen bleach and a soil dispersing agent selected from the group consisting of an ethoxylated monoamine, an ethoxylated diamine, an ethoxylated polyamine, an ethoxylated amine polymer and mixture thereof, as described hereinafter, to pretreat soiled fabrics. Indeed, the addition of such a soil dispersing agent, in a liquid composition comprising a peroxygen bleach, and optionally a bleach activator, delivers improved stain removal performance on various types of stains including greasy stains, enzymatic stains, clay/mud stains, and the like, under pretreatment conditions, as compared to the stain removal performance delivered by the same composition without said soil dispersing agent. Also, it has surprisingly been found that the liquid compositions comprising both the peroxygen bleach and said soil dispersing agent, when used to pretreat fabrics, provide improved bleaching efficacy, as compared to the same compositions without said soil dispersing agent. Thus, it has been found that the addition of a single compound, i.e., such a soil dispersing agent, in a peroxygen bleach-containing composition, delivers both improved stain removal performance and improved bleaching performance. Furthermore, it has been found that this improved stain removal performance on various stains is maintained even for peroxygen bleach-containing compositions having undergone long storage time. It is thus speculated that the oxidized form of the soil suspeding agent that may have formed in the presence of a peroxygen bleach under long storage time and/or elevated temperature still provides improved stain removal performance on various types of stains. Thus, in its broadest aspect, the present invention encompasses a process for bleaching a fabric with a liquid composition comprising from 0.01% to 15% by weight of the total composition of a peroxygen bleach, and a soil dispersing agent, said process comprising the steps of applying said liquid composition in its neat form onto at least one portion of said fabric, optionally allowing said composition to remain in contact with said fabric and then washing said fabric.
Furthermore, it has been found that the addition of a soil dispersing agent selected from the group consisting of an ethoxylated monoamine, an ethoxylated diamine, an ethoxylated polyamine, an ethoxylated amine polymer and mixture thereof, in a liquid composition formulated either as an emulsion or microemulsion, comprising a peroxygen bleach and a surfactant, reduces the viscosity of said composition, whatever the viscosity was before the addition of said soil dispersing agent. Actually, an advantage of the liquid compositions of the present invention formulated either as an emulsion or a microemulsion, is that they deliver improved stain removal performance and improved bleaching performance while delivering acceptable viscosity, without the need to add viscosity control agents. In other words, the present invention allows to formulate emulsions or microemulsions with improved overall stain removal/bleaching performance and desirable physical characteristics at reduced costs, i.e., without adding any viscosity control agent that would raise the cost formula and bulk to the compositions without contributing to the bleaching/cleaning performance of said compositions.
Another advantage of the present invention is that stable liquid emulsions or microemulsions are provided that are suitable to be used in the most efficient manner by the consumer over prolonged period of time.
Yet another advantage of the compositions according to the present invention which are formulated as emulsions or microemulsions is that they provide also excellent cleaning and/or bleaching performance when used in applications other than laundry pretreaters, such as in other laundry applications, as laundry detergents or laundry additives.
European patent application number 95870079.1 discloses laundry compositions suitable for pretreating fabrics comprising polyamines and peroxygen bleach. No ethoxylated amines, ethoxylated polyamines or ethoxylated amine polymers are disclosed.
U.S. application Ser. No. 08/663501 discloses pretreater compositions with particular chelants, a peroxygen bleach, and optional ingredients like bleach activators, polymeric soil releasing agents like sulfonated poly-ethoxy/propoxy end-capped ester oligomer. However, no ethoxylated amines, ethoxylated polyamines, or ethoxylated amine polymers are disclosed.
EP-A-271 312 discloses laundry compositions comprising a peroxyacid bleach and a soil release agent like particular alkyl and hydroxyalkyl ethers of cellulose, polymers comprising ethylene terephthalate and polyethylene oxide terephthalate. No ethoxylated amines, ethoxylated polyamines or ethoxylated amine polymers are disclosed.
WO96/12004 discloses laundry compositions comprising a lipophilic enzyme ana a primary and/or tertiary amine. These compositions provide enhanced cleaning of greasy/oily soils and stains, particularly when used in pretreatment laundering process for cleaning fabrics stained with greasy soils. The compositions exemplified comprise tetraethylenepentamine ethoxylated (15-18) but no bleach.
EP-A-112 593 discloses detergent compositions (pH=6 to 8.5) comprising ethoxylated mono- or diamines, ethoxylated polyamines and/or ethoxylated amine polymers as a clay soil removal/antiredeposition agent. Said compositions may be used in laundry pretreatment application. No peroxygen bleaches are disclosed.